A NOVEL AIRFLOW CONTROL VALVE FOR USE IN MEDICAL APPLICATIONS

Abstract

Rapid improvements in digital technology over the last two decades have led to artificial ventilators that drastically improve physicians' ability to measure and control aspects of their patients' breathing. However, the mechanical systems paired with the new digital controllers have not advanced in parallel with them. As a result, mechanical ventilators do not respond sufficiently fast to changes in operating conditions and can injure patients by allowing the air volume or pressure in their lungs to become too high. This thesis describes a new air flow control valve that can be incorporated in existing ventilators to correct this condition. The valve's low mass and short stroke result in rapid full-range motion with low actuator force and travel. These qualities also make the valve well-suited for use as a flow-change mechanism in instruments that measure airway resistance, including the Airflow Perturbation Device (APD). We describe a series of experiments that verify the valve's performance in both ventilator and APD applications.